Living Shorelines in New England: State of the Practice

Executive Summary

Increasing erosion and inundation of coastal wetlands across New England due to sea-level rise and storms threatens property and valuable natural resources. Historic practices of hard revetments and seawalls have limited effectiveness and may exacerbate erosion, destroy intertidal habitat, and alter sediment transport patterns. For these reasons, hard structural solutions are not permitted in many environmentally-sensitive coastal areas.

In the Mid-Atlantic and Gulf of Mexico states, there have been a number of applications of nature-based restorative approaches that include some combination of biotic natural media like oyster shell, natural fiber, marsh and native vegetation plantings, and the use of large sand envelopes or stone, sometimes seeded with live shellfish. These installations are designed to protect property and prevent erosion while improving habitat, water quality, and ecological condition in a way that appears natural and is consistent with the character of coastal communities and uses of the shore.

While these “living shoreline” practices are relatively new to the northeast, and practitioners have had limited experience in New England, the Coastal Zone Management Agencies of the five New England coastal states and the Northeast Regional Ocean Council (NROC) partnered with The Nature Conservancy under a grant from the National Oceanic and Atmospheric Administration (NOAA) to conduct an assessment of the State of The Practice on Living Shorelines and provide considerations for their application along the coast of New England.

For purposes of this assessment, the term living shoreline, refers to a set of coastal erosion control practices, ranging from non-structural vegetated approaches to hybrid hard structural/restorative natural methods, that address erosion and inundation in a manner that improves or protects the ecological condition of the coastline (1). Living shorelines are a coastal subset of a larger group of green infrastructure practices, which include a greater range of nature-based techniques for inland areas that address storm water control, nutrient retention, and habitat enhancement in place of hard infrastructure.

This report provides a range of practical considerations for property managers, regulators, coastal municipal leaders, scientists and practitioners, who are interested in advancing living shoreline policies and practices. The living shoreline profiles provide an overview of the techniques, conceptual designs, case studies, siting characteristics and design considerations and regulatory and review agencies that oversee the designs. Additionally, an applicability index has been developed for common living shoreline types in New England. It is intended to serve as a guide for the development of regulations and policies to explicitly incorporate these approaches into the coastal management programs of the respective states and New England’s coastal communities.

(1) - The NOAA definition: “A living shoreline is made up mostly of native material. It incorporates natural vegetation or other living, natural soft elements alone or in combination with some type of harder shoreline structure, like oyster reefs, rock sills, or anchored large wood for added stability. Living shorelines connect the land and water to stabilize the shoreline, reduce erosion, and provide ecosystem services, like valuable habitat, that enhances coastal resilience.” [18]